Pilot burner for gas heater or the like



1966 H. A. M INTOSH ET AL 33%,1

PILOT BURNER FOR GAS HEATER OR THE LIKE Filed Dec. 5, 1964 hAee/s, M501, Hus-$544. 4% KEEN United States Patent 3,231,185 PILOT BURNER FOR GAS HEATER OR THE LIKE Harold A. McIntosh, South Pasadena, and Houston Rehrig, Pasadena, Calif., assignors to Robertslraw Controls Company, Richmond, Va., a corporation of Delaware Filed Dec. 3, 1964, Ser. No. 415,744 Claims. (CL 158--113) This invention relates to a pilot burner for use with gas heaters or similar equipment.

A typical pilot burner for gas heaters includes a pilot body having an inlet and an outlet. The inlet is connected to a gas supply line and the outlet is connected to a pilot head which serves to deflect the gas discharged from the pilot body outlet. This simple type of pilot burner in which air for combustion is mixed with the gas at the outlet of the pilot body often produces an unstable flame which has a tendency to blow out.

Accordingly, it is an object of this invention to provide a pilot burner which will produce a stable flame.

It is another object of this invention to provide a pilot burner which will produce a soft flame.

It is another object of this invention to provide a pilot burner which will produce a flame which has little or no tendency to blow out.

It is a further object of this invention to provide a pilot burner which does not produce the blowtorch type flame frequently found in pilot burners of the prior art.

Another object of this invention is to provide simple, yet efficient, structural means for accomplishing the objects listed above.

Another object of this invention is to provide a pilot head having means which efliciently mixes the gas to be burned with air from the surrounding atmosphere.

The objects of the invention may be realized by providing a pilot head having means for deflecting at least a portion of the gas to be burned and for creating turbulence to mix the gas with the air. In accordance with one aspect of the invention, this means takes the form of an inwardly protruding convex dimple. It has been found that by locating the dimple in the stream of gas discharging from the pilot body, the pilot burner produces a soft stable flame having little or no tendency to blow out.

Although applicants do not wish to be held to any particular theory of operation, it is believed that the turbulence caused by positioning the dimple in the gas stream acts to draw in and intimately mix air with the gas, and that burning of this intimate mixture results in a flame having the desirable qualities referred to above.

The invention will be better understood from the following description taken in connection with the accompanying drawing and its scope is pointed out in the appended claims.

In the drawing:

FIG. 1 is a side view of the pilot burner of the present invention installed for use with a gas heater;

FIG. 2 is a plan view of the pilot burner, thermocouple, and mount;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2 showing a preferred form of the pilot burner;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3 showing the pilot head; and

FIG. 5 is a front elevation of the pilot head and a small portion of the pilot body.

FIG. 1 shows a pilot burner 5 installed for use with a main burner of a gas heater. A mount 8 is suitably secured to a support 9 by any suitable means such as screws 11 and rigidly carries the pilot burner 5 and a thermocouple 12. The thermocouple 12 is releasably held by the mount 8 as shown in FIG. 2. The main burner 7 has a plurality of apertured knobs 13 through which gas is discharged for ignition by the pilot burner. The support 9, to which the pilot burner 5 is attached, may form a part of the gas heater or may be a separate supporting structure. Gas is supplied to the pilot burner through a conduit 15. In use of the apparatus shown in FIG. 1, the pilot burner is first ignited. The pilot flame keeps the thermocouple 3 sufliciently warm so that it transmits a signal to a control apparatus (not shown) indicating that the pilot flame is burning properly. Conversely, should the pilot flame be extinguished, the thermocouple would cool quickly and transmit a signal indicating that the pilot flame is out. When it is desired to light the main burner 7, the gas supply (not shown) to the burner is turned on and gas is discharged through the apertured knobs 13. The gas so discharged will be quickly ignited by the flame from the pilot burner 5. Although the pilot burner is shown as igniting a gas heater, it should be understood that the pilot burner of this invention is usable in many different combinations and may be used anywhere that a stable flame or sure ignition is required.

The details of construction of the pilot burner of this invention may best be understood with reference to FIGS. 3 through 5. The pilot burner comprises a pilot body 21 having a passage 22 therethrough, a nozzle 23 secured within the passage in any suitable manner such as by screw threads 24, and a pilot head 25. The pilot body 21 is adapted at one end for connection to the gas supply line 15 by any suitable means such as screw threads 27. The other end 29 of pilot body 21 is of reduced cross section and defines an external shoulder 31 on the pilot body. End 29 is substantially cylindrical and has an orifice 33 passing therethrough. The nozzle 23 is a substantially cylindrical element with a passageway therethrough to direct the gas for combustion through the orifice 33.

The pilot head is a generally shovel-shaped element and may be stamped from a single sheet of metal. It comprises a first diverging channel-shaped section 39 and a second diverging channelshaped section 41. A portion 43 of the first diverging channel-shaped section is generally cylindrical and is secured to the generally cylindrical end portion 29 of the pilot body 21. When the pilot head 25 is secured to the end 29, the first channelshaped section extends longitudinally of the orifice 33 and the second diverging channel-shaped section extends laterally of the orifice 33, as shown in FIG. 3. In the preceding sentence, the word longitudinally is used to indicate that the first diverging channel-shaped section extends generally along the longitudinal :axis of the orifice 33, although it may bend slightly toward a side as viewed in FIG. 3. Likewise, the word laterally indicates that the second diverging channel-shaped section extends considerably to the side of the longitudinal axis of the orifice 33. To illustrate, but not by way of limitation, in one instance the second diverging channel-shaped section extends laterally to form an angle of about 60 with the longitudinal axis of the orifice.

Means is formed on the first diverging channel-shaped section for drawing in and mixing air with the gas discharged from the orifice 33 and to cause the pilot burner to produce a soft stable flame. This means, in the specific embodiment shown, takes the form of an inwardly protruding dimple 51. The dimple has a smoothly curved convex surface which extends into the path of gas discharging from the orifices 33, in FIG. 3. In a preferred form, the dimple extends inwardly from the first diverging channel-shaped section to a point substantially at the 1ongitudinal axis of the orifice 33. As indicated above, use of the dimple causes the pilot burner to produce a soft, stable flame which has little or no tendency to blow out.

The operation of the device should now be apparent. Gas is supplied from a source (not shown) through gas supply line 15 and then to the nozzle 23 and finally out through the orifice 33. The dimple, which extends into the path of gas emitting from the orifice 33, causes turbulence in the gas stream which effects a more intimate mixture of the gas with the surrounding air. This mixture is burned to produce a soft, stable pilot flame which may be used to ignite the gas heater 7.

Although the means for producing a soft, stable flame is illustrated as a dimple, certain other arrangements which project a convex surface into the path of gases discharging from orifice 33 may be used. For example, the dimple could be replaced by a similarly shaped object which is suitably attached to the first diverging channel-shaped section.

Although exemplary embodiments of the invention have been disclosed, it will be understood that other applications of the invention are possible and that the embodi ments disclosed may be subjected to various changes, modifications, and substitutions without necessarily departing from the spirit of the invention.

What is claimed is:

1. A pilot burner comprising:

a pilot body having a passage therethrough, said pilot body being adapted at one end for connection to a gas supply line and having an orifice for discharging gas at the other end thereof;

a pilot head attached to said pilot body, said pilot head extending longitudinally of said orifice for a first portion of its length and then extending laterally of said orifice for a second portion of its length; and

a protuberance on said first portion of said pilot head spaced from said second portion and projecting laterally inward from said first portion into the path of gas flow from said orifice for deflecting at least a portion of the gas discharged from said orifice prior to deflection by said second portion and to mix said gas with the air.

2. A pilot burner comprising:

a pilot body having a passage therethrough, said pilot body being adapted at one end for connection to a gas supply line and having an orifice for discharging gas at the other end thereof;

a pilot head attached to said pilot body, said pilot head extending longitudinally of said orifice for a first portion of its length and then extending laterally of said orifice for a second portion of its length; and

a dimple on said first portion of said pilot head extending laterally inward from said first portion into the path of gas flow from said orifice for deflecting at least a portion of the gas discharged from said orifice prior to deflection by said second portion and to mix said gas with the air.

3. A pilot burner comprising:

a pilot body having a passage therethrough, said pilot body being adapted at one end for connection to a gas supply line and having an orifice for discharging gas at the other end thereof, said orifice having a longitudinal axis;

a pilot head attached to said pilot body, said pilot head extending longitudinally of said orifice for a first portion of its length and then extending laterally of said orifice for a second portion of its length; and

a protuberance on said first portion of said pilot head spaced from said second portion and extending laterally from said first portion to a point at substantially said longitudinal axis for drawing in and mixing air with the gas discharged from said orifice upstream from said second portion.

4. A pilot burner comprising:

a pilot body having a passage therethrough, said pilot body being adapted at one end for connection to a gas supply line and having an orifice for discharging gas at the other end thereof, said orifice having a longitudinal axis;

a pilot head attached to said pilot body, said pilot head extending longitudinally of said orifice for a first portion of its length and then extending laterally of said orifice for a second portion of its length; and

an inwardly protruding dimple extending laterally from said first portion of said pilot head to a point at substantially said longitudinal axis for mixing at least a portion of the gas discharged from said orifice with the air upstream from said second portion.

5. A pilot burner comprising:

a pilot body having a passage therethrough, said pilot body being adapted at one end for connection to a gas supply line and having an orifice for discharging gas at the other end thereof, said orifice having a longitudinal axis, said other end of said pilot body being of reduced cross-sectional area and defining an external shoulder on said pilot body;

a nozzle for directing a jet of gas positioned in said passage;

a pilot head having a first diverging channel-shaped section attached to said other end of said pilot body and extending longitudinally of said orifice, said pilot head having a second diverging channel-shaped section extending laterally of said orifice; and

an inwardly protruding dimple on said first channelshaped section, said dimple being convex and extending laterally inwardly to a point at substantially said longitudinal axis for mixing at least a portion of the gas discharged from said orifice with the air upstream from said second portion.

References Cited by the Examiner UNITED STATES PATENTS 353,169 11/1886 Shipman. 3,078,916 2/1963 Loveland 158113 3,146,823 9/1964 Loveland. 3,155,143 11/1964 Jackson et al 158113 JAMES W. WESTHAVER, Primary Examiner. 

1. A PILOT BURNER COMPRISING: A PILOT BODY HAVING A PASSAGE THERETHROUGH, SAID PILOT BODY BEING ADAPTED AT ONE END FOR CONNECTIN TO A GAS SUPPLY LINE AND HAVING AN ORIFICE FOR DISCHARGING GAS AT THE OTHER END THEREOF; A PILOT HEAD ATTACHED TO SAID PILOT BODY, SAID PILOT HEAD EXTENDING LONGITUDINALLY OF SAID ORIFICE FOR A FIRST PORTION OF ITS LENGTH AND THEN EXTENDING LATERALLY OF SAID ORIFICE FOR A SECOND PORTION OF ITS LENGTH; AND A PROTUBERANCE ON SAID FIRST PORTION OF SAID PILOT HEAD SPACED FROM SAID SECOND PORTION AND PROJECTING LATERALLY INWARD FROM SAID FIRST PORTION INTO THE PATH OF GAS FLOW FROM SAID ORIFICE FOR DEFLECTING AT LEAST A PORTION OF THE GAS DISCHARGED FROM SAID ORIFICE PRIOR TO DEFLECTION BY SAID SECOND PORTION AND TO MIC SAID GAS WITH THE AIR. 